The pitch-splitting of patterns using the litho-etch-litho-etch double patterning technique (DPT) may be required at both 32nm and 22nm nodes. By splitting the layout into two masks, DPT introduces some new potential failure mechanisms. These new failure mechanisms can occur if the layer decomposition and subsequent OPC fail to account for interlayer misalignment and corner rounding of the decomposed masks. This paper will suggest novel solutions which can be taken during the OPC step to account of interlayer misalignment and corner rounding at decomposed edges. These methods will be shown to produce improved process window and reduced sensitivity to misalignment compared to a conventional OPC without interlayer awareness.

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